RESUMO
Mineral Trioxide Aggregate [MTA] has a high clinical success rate when used as the apical plug. The conventional method of using MTA as an apical plug is doneduring two treatment sessions. This study aimed to evaluate the possibility of complete filling of root canal with gutta percha and AH26 sealer immediately after the placement of MTA plug. A total of 88 single-rooted teeth were selected for this experimental study. The teeth were prepared and randomly divided into two groups of 40 each. Four teeth were considered as the positive control group and the remaining 4 as the negative controls. In group 1, MTA apical plug was placed, specimens were stored in saline solution for 24h and then filled with gutta percha and AH26 sealer. In the 2[nd] group, the roots were filled immediately after the placement of MTA. In the positive control group, the root canals were left unfilled and in the negative control group, root canals were filled with gutta percha and sealer. The specimens were then immersed in 1% methylene blue, demineralized in 5% nitric acid and cleared in methyl salicylate. Dye penetration was measured by a stereomicroscope in micrometer. T-test was used for statistical analysis. The mean dye penetration was 7813 microm in the first and 9152 um in the second group. According to t-test, the 2[nd] group had significantly greater microleakage than the first group [P<0.05]. MTA needs to be exposed to moisture for final setting and root canal obturation must be delayed until complete setting of MTA
RESUMO
Introduction: Oral cancer is one of the main hygienic problems in many countries of the world. Its prevalence in various places of the world is different and like any other disease for better understanding is necessary to understand about this diseases distribution in different parts of Iran
Objective: Determine the frequency of related factors of oral cancer in Patients who suffered from oral cancer in Guilan province in years 1996-2004
Materials and Methods: In this retrospective study we were collected oral cancer information from cancer registry center of Guilan and oral and maxillofacial surgery offices
Results: Among total samples were found 306 cases of oral Cancer which 186 patients [60.8%] were male and 120 patients [39.2%] were female. Rate of males to females were 1.55 to 1 and mean age of patients were [57.7 +/- 15.65years]. The most age incidence of suffering mouth cancer was in the 7th decades of life. In pathology, the squamus cell carcinoma with 205 cases [67%] was the most common malignant one. The second rank belonged to lymphoma with 27 cases [8.8%]. Adenocarcinoma and mucoepidermoid carcinoma, with 12 cases [3.9%] were in third place of incidence. Tongue with 53 cases [17.3%], lower lip with 35 cases [11.4%] and finally tonsil with 29 cases [9.48%], were in 1[st], 2[nd] and 3[rd] rank in incidence of malignant part of body
Conclusion: Most of the findings in this study were similar to previous studies. We need more accurate statistics to recognize the risk factors of suffering mouth cancer in various regions of country, which required integrated system of cancer registering